[DRAFT] Web Payments Working Group Charter

Note: This draft has been superseded by the October 2015 draft charter.

The mission of the Web Payments Working Group is to make payments easier and more secure on the Web, through incremental improvements to Web infrastructure that support and facilitate payments.

Fragmentation of the payment landscape is limiting the full potential of the Web, including lack of standards in areas such as:

The standards from this Working Group will reduce some areas of fragmentation, producing benefits such as:

For more background information about this group, please see the Web Payments Working Group Charter FAQ. For more information about Web Payments activities beyond the scope of this charter, see the Web Payments Interest Group description below.

@@Join the Web Payments Working Group.

End date 31 December 2017
Confidentiality Proceedings are public
Initial Chairs Nick Telford-Reed, Worldpay, Co-Chairs TBD
Initial Team Contacts
(FTE %: 50%)
Doug Schepers, Ian Jacobs
Usual Meeting Schedule Teleconferences: Weekly
Face-to-face: 2-3 per year


Under this charter, the Working Group defines standards that ease integration of the payments ecosystem into the Web for a payment initiated within a Web application.


The Working Group will standardize a set of messages and a message flow for the initiation, confirmation, and completion of a payment. Deliverables from this group will increase interoperability between payer and payee systems (for existing and future digital payment schemes), and encourage greater automation of the steps in a typical payment.

By addressing message format and flow, the group leaves open the standardization of the delivery mechanism for these messages as this will vary depending on the use case and technology stack. To support use cases where messages are proxied between payer and payee using different technologies, the group will standardize delivery mechanisms for common scenarios. This will include JavaScript APIs for the use cases where the messages are proxied between payer and payee via a Web browser and additional APIs where the messages are exchanged directly over the Web between two online entities.

This group is chartered to standardize programming interfaces; not user interfaces. This group will not define a new digital payment scheme.


digital payment scheme
A payment scheme is a set of rules and technical standards for the execution of payment transactions that are followed by adhering entities (payment processors, payers and payees). A digital payment scheme is one where transactions take place over digital networks (such as the Web). Some digital payment schemes make use internally of payment instruments from other payment schemes. How they register and communicate with internal payment instruments is beyond the scope of this charter.
digital payment instrument
A payment instrument is an account, token or other means of conducting a transaction according to a payment scheme. A digital payment instrument is one that is associated with a digital payment scheme.
digital wallet
A wallet is a container for payment instruments that affords access to them. A digital wallet holds digital payment instruments.

Payment Flow

The scope of work supports the following elements of a basic purchase triggered by payment initiation through a Web application. These standards define a high-level message flow for a payment from payer to payee either in the form of a credit push (payer initiated) or a debit pull (payee initiated) payment, and can be used to facilitate a payment from any digital payment scheme. They involve:

Negotiation of Terms
  • Payment Initiation Request, by the payee to the payer providing the terms of the payment including elements such as the accepted digital payment schemes, price, currency, recurrence, transaction type (purchase, refund, etc.), timeout and requests for any additional data that is required from the payee.
Negotiation of Payment Instruments
  • Discovery, by the payer, of their available digital payment instruments that can be used to make the payment. This is done by matching those registered by the payer with those supported by the payee (as defined in the Payment Initiation Request), while keeping information local to the payer.
  • Selection of a digital payment instrument by the payer, confirmation of the terms, and sending of any requested data back to the payee for validation.
Payment Processing and Completion
  • Execution of the payment by either payer or payee.
  • Delivery of a Payment Completion generated by the entity that executed the payment. This may contain a Proof of Payment if supported by the payment scheme.

The group will also address exceptions that may occur during these steps, including payment authorization failure, lack of available digital wallet service, and lack of suitable registered digital payment instruments.

Relation to Digital Wallets

This Working Group intends to create a standard programming interface from the Web to a payer's digital wallet so that someone with a conforming digital wallet can seamlessly make payments with a conforming application running in a conforming user agent. Because the "digital wallet" concept means different things to different audiences this charter includes the above definition to clarify the intent of this group.

This group is not developing standards for loyalty schemes and coupons, digital receipts, digital credentials, tickets, and location services. Future W3C activities may seek to increase interoperability of these or other additional digital wallet capabilities.

The group may define APIs that will also be used outside of a user agent context, such as between Web services, or from within a native application (where the browser is not the proxy between digital wallet and payee application).

On Multiple Digital Wallets

In the design of these standards, the Working Group will not assume that each user has only one digital wallet. In this charter, the phrase "the payer's digital wallet" is shorthand for "the payer's digital wallet(s)" as the payer may have multiple digital wallets.

The Working Group may consider the use case where an aggregation service acts as a more sophisticated digital wallet service or provides a wider choice of payment solutions to the payer. For example, the aggregator service might combine the functionality of multiple digital wallet services, or apply more complex algorithms to discover and collect the set of digital payment instruments available to the payer.

Security and Privacy Considerations

Security is obviously critical in payments.

For the APIs defined by this group, a key consideration is the ability to prove message integrity and authentication of all message originators. This group will work with the organizations listed in the liaisons section of the charter to help ensure API security.

There are other aspects of security (e.g., authentication of payer identity) that this group will leave to the digital payment schemes. This group will not define authentication standards (e.g., hardware-based solutions in securing transactions, or authenticating users via biometry or other mechanisms) but should be aware of industry developments to help ensure compatibility with the flows defined by this group.

In addition, W3C is developing additional security-related specifications in other groups that may be adopted in digital payment schemes. This group will follow that work to help ensure compatibility with the payment flow standards described in this charter.

Protection of the privacy of all participants in a payment is essential to maintaining the trust that payment systems are dependent upon to function. A payment process defined by this group should not disclose private details of the participants identity or other sensitive information as part of the payment process unless required by operational, legal or jurisdictional rules, or when deliberately consented to (e.g. as part of a loyalty program) by the owner of the information. The design of any public facing API should guard against the unwanted leakage of such data through exploitation of the API.

Relation to Regulatory Requirements

Digital payment schemes define how various parties meet relevant regulatory obligations. The deliverables of this group should not prevent parties from meeting those obligations.


Web Payments APIs Recommendation

Web Payments APIs will seek to increase interoperability for the following:

It will include standard request and response messages for:

It will specify the delivery mechanism for these messages in at least the following scenarios:

Interoperability Success Criteria

The group will seek interoperability between two user agents and two services that enable payers to use digital payment instruments.


Note: The group will document significant changes from this initial schedule on the group home page.
Specification FPWD CR PR Rec
Web Payments APIs March 2016 November 2016 September 2017 November 2017

Optional Deliverables

Card Payments Recommendation

A very large proportion of payments on the Web are conducted using payment cards from one of the global card schemes. The group should attempt to define a standardized specialization of the payment flow specifically for payment cards.

A generic card payment Recommendation could:

Instrument Discovery Good Practices

This charter does not include a deliverable for a standard mechanism to discover —via the payer's digital wallet— available digital payment instruments. However, the Working Group may document good practices and recommend algorithms for the discovery of payer digital payment instruments.

Test Suites

The Web Payments Working Group anticipates developing test suites for Recommendation-track specifications it develops.

Dependencies and Liaisons

Web Payments Interest Group

The Web Payments Interest Group acts as the overall coordinator at W3C of a vision for Web Payments, by gathering Web Payments Use Cases, engaging in liaisons with other payments standards bodies, and developing a high-level architecture. The group intends to explore more eCommerce scenarios than are represented in the current Working Group charter, such as digital receipts; loyalty programs and coupons; peer-to-peer payments; and harmonization of user experience in-browser, in-app, and in-store.

From time to time, the Interest Group will seek feedback from the Working Group on its evolving vision, and share information about the evolution of the Web payments technology landscape. The Interest Group may also propose new Working Groups to cover topics such as identity, credentials and commerce (including invoicing, receipts, loyalty programs, coupons, discounts, and offers). The Web Payments Interest Group also expects to provide technical input to this and other relevant W3C Working Groups, based on a detailed analysis of the relevant Web Payments Use Cases.

Other W3C Groups

Internationalization Core Working Group
Internationalization and localization review.
Privacy Interest Group
For privacy reviews.
Protocols and Formats Working Group (and successor)
To help ensure the protocols provide support for accessibility to people with disabilities.
Web Application Security
For security reviews.
Web Applications Working Group (and successor)
For review of JavaScript APIs.
Web Payments Community Group
Research and incubation of ideas for consideration by this group.
Web Security Interest Group
For security reviews.

This group will also collaborate with future W3C Working Groups developing authentication protocols.

Groups Outside W3C

ASC (Accredited Standards Committee) X9
Coordination with X9 will help achieve broad interoperability of payment systems (e.g., through alignment between Web protocols and ISO 12812).
EMVCo administers all the original specifications known as EMV, including specifications about card tokenization.
GSMA is an industry association of mobile network operators with near global coverage.
Consultations with the IETF Crypto Forum Research Group (CFRG) on cryptography, as well as the "IETF Security Area Advisory Group.
Coordination with ISO TC 68 will help achieve broad interoperability of payment systems (e.g., through alignment between Web protocols and ISO 20022).

In addition, for the Card Payments specification, the Working Group will need to collaborate with the administrators of existing global card schemes.


To be successful, the Web Payments Working Group is expected to have 10 active participants for its duration. Effective participation in Web Payments Working Group may consume .1 FTE for each participant; for editors this commitment may be higher.


This group primarily conducts its work on the public mailing list public-payments-wg@w3.org (archive). Administrative tasks may be conducted in Member-only communications.

Information about the group (deliverables, participants, face-to-face meetings, teleconferences, etc.) is available from the Web Payments Working Group home page.

Decision Policy

As explained in the Process Document (section 3.3), this group will seek to make decisions when there is consensus. When a Chair puts a question and observes dissent, after due consideration of different opinions, the Chair should put a question out for voting within the group (allowing for remote asynchronous participation -- using, for example, email and/or web-based survey techniques) and record a decision, along with any objections. The matter should then be considered resolved unless and until new information becomes available.

Any resolution first taken in a face-to-face meeting or teleconference (i.e., that does not follow a 7 day call for consensus on the mailing list) is to be considered provisional until 5 working days after the publication of the draft resolution. If no objections are raised on the mailing list within that time, the resolution will be considered to have consensus as a resolution of the Working Group.

Patent Policy

This Working Group operates under the W3C Patent Policy (5 February 2004 Version). To promote the widest adoption of Web standards, W3C seeks to issue Recommendations that can be implemented, according to this policy, on a Royalty-Free basis.

For more information about disclosure obligations for this group, please see the W3C Patent Policy Implementation.

About this Charter

This charter for the Web Payments Working Group has been created according to section 6.2 of the Process Document. In the event of a conflict between this document or the provisions of any charter and the W3C Process, the W3C Process shall take precedence.

HTML5 Apps logoDevelopment of this charter is supported in part by the European Union's 7th Research Framework Programme (FP7/ 2013-2015) under grant agreement nº611327 - HTML5 Apps

Participants of the Web Payments Interest Group
See the the Editor's Draft of the charter.

$Date: 2015/10/08 18:01:18 $